This application is related to patent applications entitled xe2x80x9cPRESSURE BASED SPONTANEOUS INFLATION INHIBITOR IN A PUMP FOR AN INFLATABLE PROSTHESISxe2x80x9d and xe2x80x9cDIAPHRAGM BASED SPONTANEOUS INFLATION INHIBITOR IN A PUMP FOR AN INFLATABLE PROSTHESIS,xe2x80x9d which were filed concurrently herewith.
This invention generally relates to a pump for inflating a prostheses and more particularly to a pump and valve assembly including a switch actuated valve that inhibits spontaneous inflation of the prosthesis.
One common treatment for male erectile dysfunction is the implantation of a penile prosthesis. Such a prosthesis typically includes a pair of inflatable cylinders that are fluidly connected to a fluid (typically liquid) reservoir via a pump and valve assembly. The two cylinders are normally implanted into the corpus cavernosae of the patient and the reservoir is typically implanted in the patient""s abdomen. The pump assembly is implanted in the scrotum. During use, the patient actuates the pump and fluid is transferred from the reservoir through the pump and into the cylinders. This results in the inflation of the cylinders and thereby produces the desired penis rigidity for a normal erection. Then, when the patient desires to deflate the cylinders, a valve assembly within the pump is actuated in a manner such that the fluid in the cylinders is released back into the reservoir. This deflation then returns the penis to a flaccid state.
With inflatable penile prostheses of current designs, spontaneous inflation of the cylinders is known to occasionally occur due to inadvertent compression of the reservoir, resulting in the undesired introduction of fluid into the cylinders. Such inadvertent inflation can be uncomfortable and embarrassing for the patient. This undesirable condition is further described below with reference to a particular prosthetic design.
With reference to FIG. 1, a known pump and valve assembly 8 for use in a penile prosthesis includes a fluid input 10 that is coupled at one end to a reservoir (not shown) and to a housing 12 at its opposite end. Also connected to the housing 12 is a fluid output 14 which, in turn, is connected at its other end to a pair of cylinders (not shown). Linking the fluid input 10 and the fluid output 14 to each other is a common passageway 33, which itself contains a valve assembly that is described in greater detail below. Common passageway 33 is also in fluid communication with a pump bulb 18 that is used to move fluid from the reservoir (not shown) to the cylinders (not shown) in order to inflate the cylinders. The valve assembly located within common passageway 33 includes a reservoir poppet 20 which is biased against a valve seat 24 by a spring 28 and a cylinder poppet 22 which is biased against a valve seat 26 by a spring 30. The springs 28 and 30 are sized so as to keep the reservoir poppet 20U and the cylinder poppet 22 biased against each respective valve seat 24 and 26 under the loads that are encountered when the reservoir is pressurized to typical abdominal pressures.
When the patient wishes to inflate the cylinders, pump bulb 18 is squeezed so as to force fluid from the pump bulb 18 into the common passageway 33. The resulting fluid flow serves to reinforce the force from the spring 28 urging the reservoir poppet 20 against valve seal 24 while at the same time causing compression of the spring 30, and thereby opening cylinder poppet 22. As a result, the fluid travels out through fluid output 14 and into the respective cylinders.
When the patient releases the pump bulb 18 a vacuum is created, thus pulling the poppet 22 back against valve seat 26 (aided by spring 30) and simultaneously pulling the reservoir poppet 20 away from its valve seat 24, against the spring 28. As a result, fluid from the reservoir is thus allowed to flow through the fluid input 10 and into the common passageway 33 passing around the reservoir poppet 20 and into the vacuous pump bulb 18. Once the pump bulb 18 has been filled, the negative pressure is eliminated and the reservoir poppet 20 returns to its normal position. This pumping action of the pump bulb 18 and valve assembly is repeated until the cylinders are~fully inflated.
To deflate the cylinders, the patient grips the housing 12 and compresses it along the axis of reservoir poppet 20 and cylinder poppet 22 in a manner such that the wall 13 of the housing 12 contacts the protruding end 21 of the reservoir poppet 20 and forces the reservoir poppet 20 away from valve seat 24. This movement, in turn, causes the reservoir poppet 20 to contact cylinder poppet 22 and force cylinder poppet 22 away from valve seat 26. As a result, both poppets 20 and 22 are moved away from their valve seats 24 and 26 and fluid moves out of the cylinders, through the fluid output 14, through common passageway 33, through the fluid input 10 and back into the reservoir. Complete deflation of the cylinders requires the patient to continuously squeeze housing 12 (hence maintaining the valves in an open position) during the entire deflation process. This can present difficulty for patients lacking manual dexterity. Furthermore, there is only limited tactile feedback to the patient through the valve and housing assembly. Thus, the patient does not necessarily know if they are squeezing too hard or not hard enough to facilitate deflation.
Although the springs 28 and 30 are sized to provide sufficient tension to keep poppets 20 and 22 firmly abutted against valve seats 24 and 26 under normal and even somewhat excessive reservoir pressures, it is possible that pressure that exceeds the force provided by the springs. could be exerted upon the reservoir during heightened physical activity or movement by the patient. Such excessive pressure on the reservoir may overcome the resistance of the spring-biased poppets 20 and 22 and thereby cause a spontaneous inflation of the cylinders. After implantation, encapsulation or calcification of the reservoir could occur. The encapsulation could lead to a more snugly enclosed reservoir, at least temporarily thus increasing the likelihood of spontaneous inflation.
The present invention includes a, pump assembly having a triple poppet arrangement wherein the poppets act as valves, such as check valves or flow valves. The cylinder poppet and the reservoir poppet are spring-biased against a valve seat, and under normal circumstances, only allows positive fluid flow when a pump bulb is compressed, thus causing an increase in fluid pressure Which is transferred to the inflatable cylinders. These two poppets function very similarly to those described with reference to the related art pump. assembly, illustrated in FIG. 1.
In addition, a switch actuated poppet is provided between the input from the reservoir and the reservoir poppet. The switch actuated poppet is coupled to a rotor and a spring loaded pusher. The spring loaded pusher is positioned adjacent the wall of the housing so that the patient can easily manipulate it, by compressing the outer wall. The interaction of the spring loaded pusher and the rotor act as an xe2x80x9con-offxe2x80x9d type switch; much like the locking mechanism in a ball point pen. Namely, with each actuation of the spring loaded pusher, the switch actuated poppet is moved from .one position to another. A momentary single squeeze moves the switch actuated poppet to either a closed position, where it forms a fluid tight seal preventing fluid flow from the reservoir towards the reservoir poppet; or to an open position wherein such fluid flow is permitted.
The switch actuated poppet is easy to operate and requires little force to be applied by the patient, thus permitting one handed operation. In addition, the positive actuation of the switching mechanism. provides a clicking sound and a perceivable tactile sensation that indicates movement and locking of the mechanisms. This simply provides some feedback to the patient, indicating a successful actuation of the switch.
The switch actuated poppet includes a locking arm that engages the reservoir poppet when the switch actuated poppet is in a closed position. When so engaged, the reservoir poppet and the cylinder poppet are caused to be opened and maintained in that position. This will allow fluid flow from the cylinders (opening the switch actuated poppet) into the reservoir during deflation. The locking mechanism will keep the switch actuated poppet in the closed position at all other times. Should an over pressurization situation occurs, the increase pressure acts to further seal the switch actuated poppet thus, spontaneous inflation is prevented.
To inflate the cylinders, the mechanism is actuated by compressing the housing. This forces the spring loaded pusher to engage the rotor moving it. to its alternate position. In so doing, the switch actuated poppet is withdrawn from its valve seat. In addition, the reservoir poppet and cylinder. poppet are each allowed to close. At this point, the device works just as described with reference to FIG. 1. A single compression of the pump bulb opens the cylinder poppet and forces fluid into the cylinders. As the pump bulb expands, the vacuum forces generated open the reservoir poppet and draw fluid from the reservoir.
When it is desired to deflate the cylinders, the switch is actuated again, causing switch actuated poppet to move to a sealing position. Since the reservoir poppet and cylinder poppet are forced open, deflation can occur. Once complete, the switch actuated poppet (in its closed position) prevents fluid from moving from the reservoir to towards the cylinders, even during an overpressurization situation.